Carrier-type endless conveyer



Jam 15, 1952A F. G. MITCHELL 2,582,381

CARRIER-TYPE ENDLESS CONVEYER Filed July 6, 1950 5 Sheets-Sheet 1 .f /g l-f4.3@ j.

INveNl-OR www Jan 15, 1952 F. G. MITCHELL CARRIER-TYPE ENDLESS CONVEYER 5 Sheets-Sheet 2 Filed July 6, 1950 v bl HIII Jan. 15, 1952 F, G, MITCHELL A2,582,881

CARRIER-TYPE ENDLESS CONVEYER Filed July 6, 195C Y 5 Sheets-Sheet .'5

.Tuve/vra R Rimba, LM., M

- palla-.M

Jan. 15, 1952 F, G, MITCHELL 2,582,881

CARRIER-TYPE ENDLESS CONVEYER l Filed July 6, 1950 5 Sheets-Sheet 4 Jan. 15, 1952 F. G. MITCHELL 2,582,881

CARRIER-TYPE ENDLESS CONVEYER Filed July 6, 1950 \5 Sheets-Sheet 5 INveNTaR e@ Jd. ma, @MMM M- Patented Jan. 15, 1952 OFFICE CARRIER-TYPE ENDLESS CONVEYER Frederick Gilbert Mitchell, London, England Application July 6, 1950, Serial No. 172,288 In GreatBritain July 8, 1949 6 Claims. 1

This invention relates to endless conveyors for dealing continuously with materials in bulk.`

The invention is concerned with endless conveyors of the type (hereinafter referred to as the carrier type) comprising an endless chain of wheeled carriages articulated to one anotherl and arranged to run on rails or an equivalent track having upper and lower runs, and an end- .less ilexible belt or the like adapted to provide the orless vertically one above the other and connected at each end of the conveyor by a loop which extends downwardly as viewed in elevation and laterally as viewed in plan; the object of the loop being to reverse the direction of travel of the carriages without changing their upright aspect. In the known arrangement referred to, the flexible belt extends beyond the runs ofthe carriage chain at the delivery andv tail ends of the conveyor, andthe extended belt portions are supported by idlers and led over end pulleys from which, at the delivery end, the material may be discharged and in front of which,

at the tailend, the material may be fed. Withthis arrangement the belt leaves the carriages when the latter are deflected by either end loopV and the belt is turned without lateral deflection on to the other run of the carriage chain.

According to the present invention a conveyor of the carrier type is so arranged that, at the ends of the conveyor, the carriage chain is guided to be turned from forward to return run and vicev versa without lateral deflection,rand the flexible belt is deflected laterally and is then guided so as to enter and leave the gap between the -upper and lower runs of the carriage chain, whereby each run of the belt is supported on the carriage chain. Y

If desired, and according to a feature of the invention, the carriage chain, at each end of the conveyor, may be taken over pulleys mounted for' rotation about horizontal axes or over equiv'- alent guides to provide between the upper and lower runs of the chain an increased gap to faci1i' tate the passage of the return lap of the flexible belt into and out of a position between the upper andlower runs of the chain.

-Inf'one arrangement according to the inven- 2 Y, tion, the flexible belt is arranged to be carried beyond the carriage chain at each end ofthe conveyor and to be passed over a suitable combination of guide pulleys designed to reverse the direction of travelof the belt and to guide it either (at the delivery end of the conveyor) into the gap between the upper and lower runs 'of the carriage chain and thus into a position in which the belt is supported by the lower carriages. or (at the tail end) out of the gap aforesaid and into a position surmounting the carriages of the upper run. The end guide pulleys may, for example, be arranged to direct the belt r in a laterally extending rectangular loop, turn' ing the belt in succession through four right angles. Alternatively, a triangular loop involving a smaller number of guide pulleys may be employed.

Some examples embodying the foregoing and other features of the invention will now be described with reference to the accompanying drawings which are to some extent diagrammatic and in which:

Figures 1 and 2 are diagrams showing in planI two alternative end turning arrangements for the conveyor belt;

Figures 3 and 4 show in side elevation andplan may be used in place of those illustrated in Figures 7 and 8.

Like reference numerals indicate like parts` throughout the drawings.

Referring to Figure 1, the conveyor comprises.

an endless chain I0 of wheeled carriages arranged to run on upper and lower tracks between a tail end ll and a delivery end l2. At each end of the conveyor the carriage chain lil is turned from forward to return run and vice versa without lateral deflection. a flexible belt- I3 which at each end of the cone veyor is extended beyond the corresponding end` v of the carriage chain and is passed over a combination of guide pulleys I4 designed to reverse The chain supports4 the direction of travel of the belt and guide it either (at the delivery end I2 of the conveyor) into the gap between the upper and lower runs oi the carriage chain, or (at the tail end II of the conveyor) out of the gap aforesaid and on to the upper carriage run. In the arrangement diagrammatically illustrated in Figure 1 the end guide pulleys I4 are arranged to direct the belt in a laterally'extendingfrectanglar'loop l'I 5', turning the path of the belt in succession throughfour right angles.

In the arrangement shown in Figure 2, the enh guide pulleys I4 are arranged, as :illustrated -to form a triangular loop I6.

Referring to Figures 3 to f-thecoriveyorf'there' f illustrated comprises an endless `chain I Aof wheeled carriages, each constituted by ein-elongated frame I1 carrying at one end an axle I0 y on which running wheels I9 are mounted;- SA' forked link is pivotallyattached to the axle I8 for-swinging vmovement about fthe axle; and provides at its endfremote from =.the f axle r'a coupling piece 2I for the attachment by a vertical-pivot,Y

offthe next adjacent carriage yof the chain.` 'The end of vthe frame remote from the .axle Ifhasa'A rigid :extension `22, the extremity :of which-is equipped with afcouplingv piece 23 similar to the couplingl 2I onA the lin-k 2li; The 'coupling piece 23 provides means fior interconnecting, by a verti-l cal pivot, the hinge :link 20 ef'ftheinext adjacent carriage (shown in ychain-lines in Figures 3 and 4f). The foregoing-arrangement vis such that,l as will be seen, the carriage chain may -iiex in a vertical direction about any'wheel `axle -l8v and inv a horizontal direction about the'vertical 'pivot bearings ofthe coupling'pieces -2-I, 23;

The wheels I9 are adapted -to run on upper and lower rail tracks 24, (Figures 5vv Yand-16).,

disposed vertically one above the other. Each carriage isV furnished with dished cross `pla-tes 26 carried-by bearersZ-I'extending upwardlyffrom the-carriage, and the plates 26 support the upper lap of the conveyor belt I3. At each end/of the general run ofthe conveyor, .the aspect oie'ach carriage is reversed, the-carriages-on the :return run being upside down in relation to `.those -in the forward run. In the arrangement shown in Figures 5 and 6 the lower, i. e. return-lap of 4the belt is supported directly by -thecarriage vaxles and the undersides ofthe carriage -frames. :lf desired, however, each carriage, in vaddition Ato `its upwardly extending belt plates 26 may gbe furnished with opposed secondary platesV (not shown) carried on oppositelydirected bearers, the secondary plates being uppermost konthe 'return run of the ychain and so being adapted v.t f

support the return lap ofthe belt.

In the end turning method shown in 4Figures 7 and 8, the following arrangement is adopted; The forward lap of the carriage'chainI `is taken over .idler wheels 39, 3l, 32, 35i-which, es shown, increase the vertical gap between .the

forward and return runs of the chain at the.

delivery end of the conveyor. The yupperf'run oi, the endless belt I3 is .takenlover guidepulleys Eil located beyond the corresponding end of the-cai`- riage -chain and thence over va terminal .pulley y from one pulley to the next. through which 'the path of the belt is deflected f belt which,as will be seen; is thus tguided into a position between the forward and return runs of the carriage chain. The vertical spacing between `successive beltpulleys disposed at right angles is arranged to 'be v"appropriate to the width of the belt which hasfto beftwisted through 90 in passing The lateral distance is arrangedto suit the site and nature of the I structure.v Figures 7 and 8 illustrate the turning arrangements at the delivery end of the conveyor; similar arrangements are at'the taill end ofrthe conveyor. y

In the end-turning method shown in Figures 9 and lOYthe following arrangement is employed;

lThe forwardlap -ofwthe carriage chain'IOV-at the delivery end of the conveyor, is guided (by anyconvenientrneans, not shown) to be *turnedy through a downwardly extending loop--but without lateral deflectioninto the return lap. The upper run'of the endless -belt I3 is taken beyond the looped turn of the carriage chain, over parallel guide pulleys 5'0, 5l and `from thence with a twist over a pulley 52 from which the belt is laterally deflected over apulley 53 andfup to apulley 54 within theloop of the carriagev chain. From thelatter tpulley the belt is directed with a 90 twist to apulley 55 under and round whichis passes, proceeding upwardly over apulley 56 into the general return run of the belt, i. e.. between the upper and lower runs ofthe carriage chain. While the drawings .again -illustrate the delivery end vof the conveyor, it y'is to besunderstood'that similar turning arrangements will beemployed at the-tail'end.

`Any' convenient driving means may beA em@- ployed for propelling the carriage' chain.

lFor example, `devices of the known creeperchain `typevmayloe employed. Such devices are indicated in chain lines in Figure 5 as compris'- ing; chains B0 carrying dogs 6| arranged toren.-l gage against the carriage 'wheel axles. As indifcatedv therevi's one creeper device ybelow the forward .run 'of vthe conveyor and a second one below ythe-return -run of the conveyor, the rst clevice supplying the 'driving power to the loaded stretch of the conveyor `and, the second device taking' the retarding load of the return run. The creeper devices may conveniently'be located near thefdelivery end of the conveyor. Alternatively I theuconveyor may vbe divided in its length 'finto aplura'lity of sections, creeper devicesl or equivaient driving means "being provided at corre-v sponding ends ofthe several sectionsso 'as to apply to each isecti'on a proportional part :of the required total propelling force, i. e. a part :prob portional'to 'theload on thatportion only-of the carrier which extends from the point of 'appli'- cation to the end of the next succeeding -section.

In carrying out this invention it is essential that the .endless `belt-constituting the actual 'supporting surface of the conveyor should befseparate from the carriage chain, since the end turning arrangements necessitate relative 'disaplacement between the belt vand 4the chain. vat

the ends of the conveyor. Quite apart from this consideration, the fact that the belt and chain are unconnected components of the conveyor is of considerable advantage in providing for variations in linear expansion of the two components. In a long run, variations in linear expansion and stretch of the belt and carriage chain may be considerable and but for the fact that the two are separate there would be difculty in accommodating these differences.

I claim:

1. An endless conveyor of the carrier type comprising in combination an endless chain of wheeled carriages articulated to one another and arranged to travel on a track having upper and lower runs, an endless ilexible belt adapted to provide the actual carrier surface for the material being conveyed and, for the greater part of its length, to be supported by and to travel with the carriage chain, guides at each. end of the conveyor for turning the carriage chain from forward to return run and vice versa without lateral deilection, and means at each end of the conveyor for guiding the flexible belt by lateral deflection into and out of the gap between the upper and lower runs of the carriage chain.

2. An endless conveyor of the carrier type comprising in combination an endless chain of wheeled carriages articulated to one another and arranged to travel on a track having upper and lower runs, an endless flexible belt adapted to provide the actual carrier surface for the material being conveyed and, for the greater part of its length, to be supported by and to travel with the carriage chain, guides at each end of the conveyor for turning the carriage chain from forward to return run and vice versa without lateral deflection and guide pulley combinations at each end of the conveyor for directing the belt beyond the corresponding ends of the chain and in laterally extending loops into and out of the gap between the upper and lower runs of the carriage chain.

3. An endless conveyor as claimed in claim 2 in which each of the aforesaid guide pulley combinations is arranged to direct the belt in a laterally extending rectangular loop, turning the direction of travel of the belt in succession through four right angles.

4. An endless conveyor as claimed in claim 2 in which each guide pulley combination is arranged to direct the belt in a laterally extending triangular loop.

5. An endless conveyor as claimed in claim 2 in which each guide pulley combination is arranged to cause the belt to follow a path which, in relation to the general run of the conveyor, is deflected in both lateral and vertical directions.

6. An endless conveyor as claimed in claim 1 in which the carriage chain, at the ends of the conveyor, is taken over guide members arranged to provide between the upper and lower runs of the chain an increased gap to facilitate the passage of the return lap of the exible belt into and out of a position between the upper and lower runs of the chain.

FREDERICK GILBERT MITCHELL.

No references cited. 

